Weir-in-a-box: Keeps pipe full, but can it measure flowrate?
Weir-in-a-box: Keeps pipe full, but can it measure flowrate?
(OP)
I've encountered an application where a customer used a large 'box' with an internal Weir to insure that the upstream pipe is always full. The pipe is 12" diameter, and the 'box' is around 1x1x1 meters in outside dimension. The internal Weir divides the box in half and is about 3/4 of the height. Flow enters at the bottom ofn one side of the Weir, flows over the Weir, and flows out the bottom of the other side. The purpose of this device is to always keep the upstream pipe full. But now would be very convenient to get an approximate flowrate from it by measuring the height of the fluid (slurry in this case) flowing over the Weir.
Has anyone had experience with such a device? If so, please comment on your experience of this "Weir-in-a-box" flowmeter? Thanks very much.
Bob Maron
Has anyone had experience with such a device? If so, please comment on your experience of this "Weir-in-a-box" flowmeter? Thanks very much.
Bob Maron





RE: Weir-in-a-box: Keeps pipe full, but can it measure flowrate?
What's the reason for keepinfg the pipeline full, I have experience with mining slurry, it sounds like it would sand up.
Roy
RE: Weir-in-a-box: Keeps pipe full, but can it measure flowrate?
Keith Cress
kcress - http://www.flaminsystems.com
RE: Weir-in-a-box: Keeps pipe full, but can it measure flowrate?
If you could block the exit briefly and catch the resulting overflow you could calibrate the weir.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Weir-in-a-box: Keeps pipe full, but can it measure flowrate?
RE: Weir-in-a-box: Keeps pipe full, but can it measure flowrate?
RE: Weir-in-a-box: Keeps pipe full, but can it measure flowrate?
For a sluice, fabricate a thin channel, with wide flanges, say a 1" web and 4" flanges (or whatever you need to capture the depth of the overflow) in say 18 gage metal. Lay the channel on top of the weir, web down, and redirect a fraction of the weir's flow into the bucket. Traverse the channel across the weir a web at a time and sum the individual flowrates.
If it's a notch weir, you can find formulas in old M.E. handbooks.
Mike Halloran
Pembroke Pines, FL, USA
RE: Weir-in-a-box: Keeps pipe full, but can it measure flowrate?
If the line is open at both ends another way of checking flow would be to put something in and time it from one end to the other.
What sort of slurry?
Roy
RE: Weir-in-a-box: Keeps pipe full, but can it measure flowrate?
I know about using 'tracers' to check flowrate, but that's only a velocity check, and if there are sanded sections of significant length, then the procedure will not accurately the volumetric flowrate. Right?
Roy, do you work with slurry flows?
Any other comments Roy?
Thanks in advance.
Bob
RE: Weir-in-a-box: Keeps pipe full, but can it measure flowrate?
Yes,I worked in mining, mainly copper & gold for many years but not so much now.
I assume you don't have a vertical section to place your meter, on a horizontal line you will get a flow profile with the heavier portion traveling slower along the bottom.
Interesting new meter, have you tried it at different locations on the pipe, 3 o'clock, 6 o'clock etc?
Have you compared it with a mag flow on vertical line, e.g. cyclone feed?
I assume it allows for the two layers, steel and rubber.
Regards
Roy roy_matson at yahoo dot ca
RE: Weir-in-a-box: Keeps pipe full, but can it measure flowrate?
Bill
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